Light bulb



FIG. 1 is a perspective view of a first embodiment of a lighting apparatus;

FIG. 2 is a side view thereof, all other side views being the same as the side view;

FIG. 3 is a bottom view thereof; and,

FIG. 4 is a sectional view thereof, taken along the line 4-4 of FIG. 2.

The broken line showing of the upper portion is included for the purpose of illustrating only and forms no part of the claimed design. 

CLAIM The ornamental design for a light bulb, as shown and described. 